Fuel injection system



Jan. 17, R, ENSIGN I I 1,894,510

FUEL INJEcTI'oN SYSTEM Filed Oct. 10, 1928 3 Sheets-Sheet l Jan.17,1933.

R. F. ENSIGN FUEL INJECTION SYSTEM 3 Shets-Sheet '2 Filed Oct. .10. 19282 5 WW 6 a c o .3 a r a a 6 Z in? m H a 5 x I 114 W J z a a I 6 0/ Q W WH b ,0 a 7 a I a 4 m a M 0, WW 4 J w 3 a E l :Z W Y L: a J 6 6 J J a 6 rJ 5 3 J 6 8 2 8 Irilil wk 6 V 19M 7 A7 M V 9 6 v 0 7 0 0 G 172062? for.Fay F 27175494 Jan. 17, 1933. R, E 5 1,894,510 I FUEL INJECTION SYSTEMFiled Oct. 10, 1928 s Sheets-Sheet s E29 .9. v 35:. I I

Patented Jan. 17, 1933 UNITED STATES PAT NT OFFICE.

ROY F. ENSIGN, OF SOUTH PAS ADENA, CALIFORNIA, ASSIGNOR TO ENSIGNCARBURETOR 60., LTD., OF HUNTINGTON PARK, CALIFORNIA, A CORPORATION OFCALIFORNIA FUEL INJECTION sYsrnu Application filed October 10, 1928.Serial No. 311,512.

The present invention has to do generally with systems for supplyingfuel to internal combustion engines, and relates more particularly to afuel injection system for use in engines of this general type.

A primary purpose of the invention is to enable an engine equippedtherewith to operate with greater power and efliciency than isobtainable by the use of the usual fuel supply systems. In order thatthe features embodied in the invention which bring about improved engineperformance may be understood most clearly, mention is made at theoutset of certain shortcomings of the usual fuel supply systems and howsuch disadvantages are overcome by the present system.

The most common systems for distributing fuel to the engine cylindersembody the use of a carbureter, wherein the fuel is drawn into thecylinders by virtue of a restriction in a passage through which fuel andair are drawn into the engine manifold. In addition to this restriction,however, numerous fuel delivery devices such as spray tubes and the likeare necessarily placed in the path of the intake air, and as a result,loss of power to the engine is caused in decreasing its volumetricefliciency. Furthermore, the fuel contained in the mixture formed in acarbureter, though partially vaporized, is for the most art held insuspension in the air stream. Ks a result, when the mixture is drawninto the engine manifold and the velocity of flow reduced, the suspendedfuel.

particles tend to separate from the air to a certain extent, and todeposit upon the walls of the manifold, thereby resulting in unevendistribution of fuel to the cylinders. In a carbureter system, the fuelused necessarilyj must be comparatively volatile; it being restricted tovolatiles in that the heavier and cheaper grades of fuels are difficultto vaporize, to a sufficient extent to bring about their ignition andcomplete combustion in the engine cylinders.

In certain general types of injection systems, constant compression ismaintained in the cylinders at all times, and the speed and ower of theengine controlled by the amount 0 of liquid fuel injected into thecylinders.

,fuel into the cylinders.

The quantity of fuel discharged generally is mechanically controlled bya pump arrangement actuated by the engine, the delivery from whichdepends upon the engine speed. This system of metering the fuelobviously is inferior to the air metering system of the carburetortoward maintaining the correct and most economical fuel and airmixtures.

In the present type of fuel injection system the flow of'intake air tothe engine is entirely unrestricted by fuel delivery devices such as jetand spray tubes, in fact, a portion of the air is pumped into thecylinders. In addition, the fuel, in amount necessary for most eflicientengine performance at any speed 'or load, is evenly distributed andpumped through separate passage lines into each cylinder. Efficientoperation is further gained by the present system in that the fuel isaccurately metered in accordance with the amount of air used, andsubsequently is injected under pressure and separately from the main airsupply, directly into the engine sure, is sprayed into the cylinders andvaporized and atomized to such extent as to permit combustion of heaviergrades of fuel than could be used by merely drawing the Since the fuelis pumped directly into the cylinders, separation and unevendistribution of fuel to the cylinders cannot Occur.

Inasmuch as the fuel is metered according to the amount of intake airused, and since the fuel is actually mixed with a quantity of air beforeinjection into the cylinders, more accurate control andmore thoroughadmixture of fuel and air is effected thancan be accomplished by merelyinjecting, by the usual system, a quantity of fuel into the cylindersandcontrolling that quantity by some mechanical means actuated by theengine;

As will later be made apparent/the present system includes the desirablefeatures of both t e carbureter and common injection systems,

and without the disadvantages mentioned above.

The above and numerous additional features of the present system will bemost readily and clearly understood from the following detaileddescription of the invention, reference being made throughout thedescription to the annexed drawings, in which:

Figure 1 is a detailed view of the fuel injection system applied to aninternal combustionengine, the various portions of the system beingshown in section;

Fig. 2 is a vertical section through the pump and fuel reservoir takenon line 2-2 of Fig. 1;

Fig. 3 is a fragmentary and enlarged perspective view of the pump fuelchambers through section 33 of Fig. 1;

Fig. 4 is a horizontal section through the fuel reservoir on line 44 ofFig. 1;

'Fig. 5 is a section on line 5-5 of Fig. 1; Fig. 6 is a section on line6-6 of Fig. 1; Fi 7 is a fragmentary side elevation of the alrcontrolled device as viewed in the direction of arrow A in Fig. 1;

Fig. 8 is a section on line 88 of Fig.1; and

Fig. 9 is a section'on line 9-9 of Fig. 8. Referring first to Fig. 1, aninlet air control device, generally indicated at T, is provided for relating the flow of air to the engine mani' old M, passages 15 extendingfrom the manifold to communicate one each with each of the enginecylinders C,one pas sage and one cylinder only being shown; Intermittent fiow of air from passage 15 to the cylinder is controlled bythe engine valve V. A liquid fuel reservoir R communicates with the aircontrol device T in such a manner that the amount of fuel fed to thepump P from the reservoir at all times is proportioned or metered inaccordance with the amount of air being taken into the engine. The fuelis discharged from the pump P and under pressure through lines 16 to theinjector valves J, (of which there is one for each cylinder) from whenceit is discharged into the engine cylinder.

With particular reference to the air control device T; a tube-shapedbody portion 17 is joined to the engine manifold M as at 18, and is openat its upper end to provide an air inletI. As illustrated in Fig. 8, thebody 17 is shaped at its side to provide a separate and auxiliarycircular valve chamber 20 closed at its outer end by means of plug 21.The lower portion of the body has a cylindrical bore 17 (1 within whichis a throttle valve 22, mounted upon a horizontally extending shaft 23,the latter being journaled in the body at 23a and in plug 21 at 21a asshown. The throttle valve 22 is actuated to control the flow of airthrough bore 17a by suitable connection (not shown) with arm 24, mountedon the end of the shaft 23. Intermediate the upper and 40a fitted intothe cover bore 41.

lower ends of bore 17a isa'comparatively restricted portion or venturi25, into the throat of which a passage 26 opens, the venturi serving inthe usual manner to create depression through the passage.

Opening into the sides of the auxiliary valve chamber 20 is a pair ofoppositely disposed ports 28 and 29, the former communicating throughpassage or conduit 30, with the Venturi opening 26 and depressionpassage 32 leading to the depression chamber 33, and port 29communicating with bore 17a of the inlet through passage 31 outside theventuri. An auxiliary valve 34 is mounted on shaft 23 in chamber 20, andis adapted, upon rotation of the shaft, to control the flow 0 air frompassage 31 through the auxiliary valve chamber and into passage 30. Itis seen that valve 34 is shaped to provide arms 34a and 34?), the endsof which slidably engage the cylindrical wall of chamber 20, thatportion of the valve between the arms being cut away as at 35 to permitthe flow of air,

as indicated by the arrows in Fig. 9, from port 29 to port 28 in theposition shown.

It may be noted at this time that the illustrated position of valve 34corresponds to anintermediate position of adjustment of throttle valve22, and that by moving valve 22 either to its open or closed position,port 28 is caused to be closed by the auxiliary valve ends 3411 or 346respectively. Thus it is seen that during intermediate adjustments ofthrottle valve 22, by-pass of air from the inlet I to the depressionline 32 is effected through passages 30 and 31 and the auxiliary valvechamber. However, at Wide open and closed positions of the throttlevalve, the by-pass is closed and the full depression occurring at thethroat of the venturi 25' is transmitted directly through line 32 to thedepression chamber 33. As will later be seen, the purpose of theauxiliary valve arrangement is to modify the fuel metering, and it maybe stated that other devices having similar operating characteristicsmay be used in the invention.

Reservoir R is mounted upon the cover 35 of the pump body 36, the walls37 of the reservoir being formed integrally with cover 35 or in anyother suitable manner. Mounted on the reservoir cover 38 is a cup 39having a bore 39a defining the depression chamber 33, pipe 32 extendingthrough the side of the cup as at 38a to open into the depressionchamber. At one side in the bottom 38b of cup 39 is an opening 39?)communicating through the fluid passage 42 with an accelcrating well 40formed by an inverted cup A restricted orifice or air bleed 40b isdrilled in the top of cup 40, forming the accelerating well, the purposeof orifice 40?) being primarily to allow surging of the fuel in theaccelerating well as will be described later.

pump P is As shown in Fig. 4, the float chamber 44 communicates with thedepression chamber 33 by means of opening 45, liquid flow through thisopening being adjustable by needle valve 46 mounted upon the reservoirwall 37 as at 47. Although the flow of fuel into reservoir 44 from afeed supply line 105 may be controlled by float 48 by numerous wellknown valve devices, I have shown, as typical, the float controlledvalve G (see Fig. 2) wherein the feed flow to the reservoir 44 throughorifice 106 and passage 107 is controlled by needle valve 108 resting onthe float arm 109. The float is cut away as at 48a, see Fig. 4, in orderto clear the accelerating well 40 and needle valve 46.

Within the depression chamber 33 is an inverted cup 50 depending fromatubular stem 51 threaded through plug 54 in the upper end of bore 39a.Cup 50 is vertically adjustable by turning nut 51a on the end of stem51. The vertical position of cup 50 1s such that its lower edge is belowthe liquid level L in the-fuel reservoir and normally below the liquidlevel in the depression chamber. Thus the skirt portion of the cup maybe considered as forming a liquid seal between chamber 130, withinthe'cup, and the depression chamber 33, and by adjusting the cupvertically, the depth of the liquid seal may be varied as desired. 1

A tube 55. which serves essentially as a weir, s stationarily mounted inthe bottom 38?) of cup 39, the weir being tightly fitted within bore531) and extended downward into the upper end of pump actuating shaft56, which will be more fully described at a later point. The weir isfitted into the upper end of the pump shaft with suflicient looseness topermit relative rotation of the latter. It will suffice to state atpresent that the fuel operated in timed relation with the engine andthat the pump takes its suction of fuel and air through bore 57 drilledlongitudinally within shaft 56 and communieating through weir 55 withchamber 130. Also it may be mentioned at this time that the depressionin chamber 130 created by the pump suction may be greater, in accordancewith the speed of the engine, than the depression in chamber 33 causedby the flow of air in the venturi past opening 26, and as a result theliquid level L in chamber 130 is caused to rise and the level L" inchamber 33 to fall. The upper end of weir 55 projects somewhat above thenormal fuel level in chamber 130, but as the pump depression is appliedto chamber 130, the fuel level rises, as mentioned, and the fueloverflows the weir and is delvered downward'through the bore 57 to thepump.

The fuel supply to chamber- 33 through orifice 45 is regulatedby needlevalve 46, the

latter preferably being set so that the rate at which fuel which may"betaken into the depression chamber under the pressure head of theliquid in the reservoir is about that rate at which the engine takesfuel operating at highest speed. Under condition of acceleration or loadincrease when a maximum and still higher rate of fuel consumption occursas the engine picks up speed or takes on load,

excess fuel as'may be required is rendered instantly available from theaccelerating well 40. Fuel delivery from the accelerating well 40 occursby way of passages 42 and 39b,

which preferably are less restricted than the valve controlled opening45 so as to allow free flow from the accelerating well to the depressionchamber, and thereby render the livery to the pump. That is, by makingpassages 42 and 39b of somewhat larger size than the effective opening45, which is predetermined for high speed operation as mentioned, thefuel content of the accelerating well is rendered more quickly availablefor being taken into the depression chamber 33, than fuel taken directlyfrom the float chamber through 45; and this will be especially true incase opening is made sufliciently large as to not restrict the air bleedinto the well. As stated however, the rate of dumping of theaccelerating well may be retarded, if desired, by making opening 40bsufliciently small that the air bleed into the well therethrough assuction is applied through chamber 33, will be so restricted as to causethe fuel in the well to be held back so that its flow from the well willbe extended over a longer period.

I will now describe generally the procedure by which the fuel is meteredin accordance with the amount of air flowing through the venturi 25 fordelivery to the pump through bore 57 of shaft 56. Assuming first thatthe throttle valve 22 is-in its idling speed position, and with arm 34?)of the auxiliary valve 34 closing port 29, depression brought about bythe flow of intake air past the throat of venturi 25 is transmitteddirectly to the depression chamber 33. The lower end 50?) of cup 50 issubmerged somewhat below the liquid level L in the reservoir 44 in orderthat at idling speed and when the liquid level L in the depressionchamber becomes lowered due to the rising of fuel in cup 50 and intotube 55, there 1s created an effective liquid head in reservoir 44corresponding to the height between the normal reservoir level L and thelevel L of liquid in chamber 33. This added head s'serves to increasethe 'fuel in the well instantly available for dethrough tube 55 in orderto give a compara tively rich fuel mixture in the engine cylindens atidling speed. During idling speeds the liquid level L in the depressionchamber mayor may not drop to the lower edge of cup 50, this beingcontrollable by regulating thevertical position of the cup. Under eithercircumstance, a rich'fuel' mixture is delivered through the weir to thepump since in case the level L does drop to the lower edge of cup 50 andthereby permit some air to e drawn into chamber 130 from chamber 33,this amount of airowill be comparatively small and will not greatlydilute the fuel. As the engine speed increases, and assuming the upperend of the weir to be unrestricted, greater amounts of air will be drawninto chamber 130 beneath the lower edge of the cu due to the increase inpump suction. In

or er to prevent syphoning of the fuel through the weir, an orifice 50ais drilled in the top of cup 50, the size of this orifice necessarilybeing only suflicient to prevent such syphoning. Of course a smallamount of air will be drawn in through the orifice and mixed with thefuel taken to the pump, although this air is more or less incidental tothe main flow which occurs beneath-the cup. And in saying that the airtaken into the cup chamber through orifice 50a is incidental to the mainflow passing beneath the cup, I mean that the flow through 50a will beso restricted that it will not relieve the pressure differential betweenchambers 130 and 33, due

7 to the comparatively greater suction being applied to 130 from thepump than that transmitted to 33 from the venturi. In other words, theair bleed through 50a will prevent syphonin of the fuel over the weirbut will not be su cient to equalize the pressures in chambers 130 and33.

With the throttle valve 22 in an intermedi-- ate position as shown inFig. 1, air is bypassed from the inlet I to line 32 as described,thereby lessening the depression in chamber 33 below that whichwouldnormally result from the flow of air through the venturi atintermediate speeds. This correspondingly decreases the proportionalamount of fuel discharged over tube 55 into the pump suction bore 57although the actual amount is greater, with the result that atintermediate speed the engine is supplied with somewhat leaner mixture.

Should the engine be required to accelerate from idling to high speed, aload is imposed upon the engine in accordance with the accelerationrequired. Inasmuch as it is desirable that the engine, when under load,be supplied with a fuel mixture richer than that normally required, theamount of fuel necessary to take care of the accelerating load is madeavailable through the accelerating or auxiliary Well 40. Therefore, uponsudden depression in chamber 33 due to wide opening of the throttle, thefuel in well 40 is drawn into tube 55 as described until the engine hasattained its desired speed, after which the amount of fuel which wouldnormally flow through opening 45 is suflicient to provide suitablemixture for the engine at high speed. It will be noted, in addition,that in the high speed position of throttle 22,

port 29 is again covered by the auxiliary valve arm 34a and the fuelmixture proportionately enrichened over that supplied during duringacceleration. In other words the rate at which well 40 empties may becontrolled by regulating the size of orifice 406. During high speeds andwith the well exhausted of its contents, a comparatively small amount ofair may enter the depression chamber by way opening 40?) and bubble upthrough the liquid in the depression chamber, this amlount of air beinginsufficient, though to appreciably affect the depression in saidchamber communicated fromthe venturi.

Communication is established between the air inlet I and the space abovethe liquid level I L in the reservoir by means of a compensating line60. By the provision of line 60, it will be seen that should an airfilter or any other attachment be applied to inletI which would tend tocause a depression is compensated in that constant relative pressureconditions are maintained between the reservoir and the air inlet Iregardless of obstructions to flow of the air before it enters theinlet. Also, as a safety measure, it will be seen that vapors from thefuel reservoir are kept within the system, that is, they are dischargedinto the intake air stream rather than to the atmosphere.

As shown'in Fig. 6, the pump body 36 is provided with a'plurality ofvertically,eX- tending bores 61 containing pump plungers 62 and spacedsymmetrically about shaft 56. A plunger 62 is provided for each cylinderof the engine, and although I have typically illustrated a pump for usewith a four cylinder engine, it will be understood that the number ofplungers may be increased or decreased to accommodate an engine havingany number of cylinders. The plungers are provided with enlargedcylindrical heads 62a within correspondingly enlarged bores 61a, theplungers being urged upwardly by means of springs 63 contained with nbores 61a and around the pistons 62. Bores 61a open at their upper endinto space S in the body, this space being closed at its lower end bymeans of the body partition 3605.

A flanged block 65 is fitted into the lower end of the body 36 in bore360, shaft 56 being journaled in the block at 65a as well as inpartition 36a at 66 and in the body cover at (36a. Confined between theflange 65b of block and the lower end of body 36 is a ring 67 oontaininports 68, one each for each piston chamber 5', and controlled by checkvalves 70. The check valves'are contained within bores 71 in the blockand ring 67, these bores opening into the fuel passages 72. It is seenthat communication is established between chamber C and the fuel line16, terminally communicating with passage 72 as at 16a, by way of ports68, bore 71 and passage 72. As clearly shown in Figs. 3 and 6, the upperend of block 65 within the body bore 360 is shaped to provide aplurality of radial troughs 75, one for each of the pump plungers 62 andserving as fuel supply chambers for the pump chambers C. Each trough isseen to be formed by upwardly and outwardly extending crest portions 76and down- Wardly inclined valleys 76a between the crests, body ports 78being formed in the wall of bore 360 and establishing communicationbetween the outer and lower end of troughs and the pump chamber C.

A conically shaped flange head 80 is rigidly mounted on shaft 56 and hasslight clearance at its top and bottom from the body partition 36a andblock- 65 as shown, and is spaced at 81 from the crests 76-0f troughs 75to clear passages 82, which will later be described. A downwardlyinclined distributor tube 83 extends through the head 80 incommunication with the shaft bore 57 and pref-- erably projects slightlyfrom the outer con-1 ical face of the head. Thus it is seen that byrotating shaft 56 by suitable drive means, from the engine, thedistributor tube 83 is caused to rotate with shaft 56 and-tosuccessively deliver fuel taken into bore 57 through the tubular weir55, as previously described, to each of the trough chambers" 75.Inclined passages 82, extending betw en the plunger bores 61a and theclearance ace 81, are provided in order that should leakage of the fuelbetween the plungers 62 and their bores 61 take place during thecompression stroke of the piston, and the fuel become forced into theupper bores 61a, it may then drain back into troughs 75 through thepassages 82.

Within the upper portion of space S in the pump body 36 is a circularand inclined swash plate 85 adapted to bear on its lower face F againstthe upper end of the plunger heads 62a and to impart verticalreciprocatory motion to the plungers when shaft 56 is rotated. The swashplate is mounted on the eccentr c hub 86, positioned on the shaft by Imeans of set screw 87, and is confined between bearings 89 carried inthe annular hearing rings 88 extending around the lower portion 86a ofthe hub. The bearing assembly and the swash plate are held in place onthe hub by retention ring 90a mounted on the hub by means of set screws90.

The lower face F of the swash plate and the upper ends of the plungerheads are pre-' successively forced downward on their compressionstroke, and likewise are permitted successively to be urged upward bysprings 63 on their suction stroke, all in sequence corresponding to themotion of the swash plate. In order to lubricate the swash plate andbearing assembly, the upper body space S may be permitted to communicatethrough openings 91 and 9101 with the vapor space in theengine crankcase (not shown) to the end that oil vapors from the crank case passthrough space S in sufficient amount to furnish the desired lubrication.

An injector valve J is mounted upon the engine head above cylinder Cand, as will later be seen, serves to discharge fuel under pressure fromline 16 into cylinder C. The

illustrated type of injector valve is merely typical of numerous devicesof this general nature that may be used for injecting fuel into thecylinders, and therefore the invention is not to be considered aslimited to the use of this particular form of injector valve. The valveis seen to have a body 92 threaded into the engine head H at 92a, therebeing formed in the body a pair of vertically extending co-axial bores93 and 93a, the latter terminating at its lower end in an orifice O. Theinjector valve body has a horizontally extending bore 95 communicatingat its inner end with bore 93 and at its outer endwith the fuel supplyline 16 terminating in the body within bushing 94. Thus it is seen thatthe plunger compression chamber C communicates with the engine cylinderC by way of line 16, bores 93 and 93a and orifice O.

Confined between the cover 96 0f the injector valve and its body 92 is aflexible diaphragm 97, upon which is centrally mounteda head 98. Aneedle valve 99 is threaded in-, to the lower end of head 98 and dependstherefrom through bores 93 and 93a to seat in the orifice O. The headncl therefore the needle valve are urged do nward by means of spring 100confined between the head and valve cover 96. It will be noted that thediaphragm, is spaced from the body and cover of the injector valve J inconnection with the pump P. It willbe seen that due to the continuousdistribution of fuel to the supply C. As the plunger 62 moves upwardfrom its lowermost position, during which movement check valve 68remains closed, suction is developed in chamber C, which, when thepiston moves to sufficient height to uncover port 78, causes fuel andair, that is air supplemental to the main air feed, to be drawn throughthat port into the chamber. It will be noted that port 78 is open for acomparatively short time only. Upon downward movement of the plunger,the charge in chamber C is compressed causing check valve to be openedand thefuel, to be discharged under pressure into line 16. At anintermediate point in the plunger compression stroke the pressuredeveloped in line 16 acting upon diaphragm 97 is sufficient to raise theneedle valve 99 from its seat and to permit fuel to be dischargedthrough orifice 0 into the engine cylinder. When the plunger has reachedthe end of its compression stroke, and a certain amount of depressionhas taken place in line 16 due to the discharge through orifice O, thepressure on the under side of diaphragm 97 becomes insuflicient tocounteract the thrust of spring 100, and the needle valve 99 istherefore returned to its seating position to close the intake of fueland supplemental air to the cylinder.

Plunger bores 61, and therefore the volume of plunger chamber C, may beof any suitable size, as in some instances it may bedesirable to pumpconsiderable supplemental air into the engine cylinders by means of thefuel pump. The limiting factor is determining the size of the plungerchambers C is, of course, the power required to compress and injectlarge amounts of air with the fuel.

. It will be seen from the foregoing, that the point of initial fueldischarge into the engine cylinder is finally determined by the injectorvalve, that is, by regulating thetension ofspring 100 or of thediaphragm, the pressure that must be exerted on the under face of thediaphragm in order to unseat the needle valve may be predetermined. andmay be caused to take place at substantially any intermediate point inthe plunger compres-,

sion stroke. In a like manner. the point at which fuel intake to theengine cylinder is discontinued occurs when the plunger has reached theend of its stroke and when the pressure in line 16 attains a valuecorresponding to the adjustment of the injector valve.

Due to the fact that the discharge from the pump chambers is acompressible mixture composed of fuel and air, the injection of themixture into the engine cylinders may be determined or timed accordingto pressure conditions. That is, the pressure of the mixture may bebrought to suitable value for discharge into the engine cylinders atsubstantially any point of the piston stroke, and due to the pressureand compressibility of the charge, the period of discharge into thecylinder may be regulated as previously described.

As a typical means for driving the pump, I have provided a shaft 112driven by the engine crank shaft 110 through gears 111 and 111a. Shaft112 is drivingly connected to the pump shaft 56 by gears 113 and 113a.Preferably, the driving arrangement is so geared that the pump shaft isdriven at half the speed of the engine crank shaft. By proper adjustmentand timing of the pump drive and the injector valve, discharge of fuelinto the "cylinders may be maintained during substanmore or lessdependent upon the particular engine used, and the conditions underwhich that engine is required to operate.

During operation of the invention as described, it is seen that as theengine speed increases, increasing amounts of fuel are sup plied byincreasing the proportion of fuel to air taken into the plunger chambersC. That is, with passage 57 in the pump shaft 56 unrestricted, aconstant volume of air is drawn into chambers C after the plungers havecompleted their suction stroke, and additional amounts of fuel aredelivered to the chambers as acceleration takes place in accordance withthe depression maintained in chamber 33 by virtue of the fuel meteringsystem. Here we have a condition under which the actual quantities offuel taken into the pump are metered in'the depression chamber asdescribed, in accordance with the amount of air flowing to the enginethrough the venturi, and the fuel to air ratio of the mixture taken intothe pump, is varied as the amount of metered fuel varies. It may bedesirable under certain conditions, for the system to operate in such amanner that for all speeds of the engine, substantially constant andrelatively rich mixtures of fuel and supplemental air will be dischargedfrom the plunger chambers to the engine cylinders. Thus by controllingthe amount of air drawn throughpassage 57 in accordance with the amountof fuel flowing therethrough, a mixture sufiiciently rich foraccelerating pur poses may be held in the feed line 16 at all times.This is advantageous in that when it is desired to accelerate the enginespeeds, there is instantly available for discharge into the cylinders amixture sufficiently rich for achas no appreciable effect on the actualratio of the main air supply flowing through the venturi, to fuel, sincethe quantity of fuel delivered to the pump is independent of thesupplemental air mixed with it.

In order for the system to operate under these conditions, I haveprovided a needle valve 114 extending vertically through the bore oftubular stem 51 carrying the inverted adjustable cup 50, the needlevalve being tapered at its lower end to project into the upper end ofthe tubular weir 55. As will later be seen the needle valve isvertically adjustable to control the passage of air to the plungerchambers by way of the pump shaft bore 57. A support 115 is carried onthe upper face of plug 54, and a hub 116 is pivotally mounted upon thesupport,

the hub having angularly extending arms 117 and 118, the former beingpivotally joined at- 119 to the upper end of the needle valve. Arm 118is pivotally connected at 120 to a rod 121 which, in turn, is pivotallyjoined at 122 of lever arm 123 rigidly mounted on the throttle valveshaft 23. The relative position of the throttle valve 22, lever arm 123and needle valve 114 are such that when the throttle valve is in itsidling speed position, the tapered end of the needle valve more or lessclosely approaches and restricts the upper end opening of the tubularweir, and when the throttle valve is in its open position needle valve114' is raised inorder to permit free passage of air from the depressionchamber into the plunger chambers.

Thus it will be seen that during idling speed in which the amount offuel delivered to the pump is comparatively small, the air intake by wayof the tubular weir is somewhat restricted due to the position of theneedle valve. As the engine accelerates from idlingspeed, the depressionin chamber 33 is increased due to the action of the venturi, and theamount of fuel delivered to the plunger correspondingly increased aspreviously described. Opening movement of the throttle valve, however,is accompanied by movement of lever arm 123 and the raising of theneedle valve to permit increased flow of air to the plunger chamber,said flow of air bewith the increase of fuel delivery in such proportionthat the ratio of fuel to air in the mixture fed to the pump remainingmore or less constant. Due to the upward movement of the needle valve,this condition may prevail at all speeds including the maximum speedcorresponding to the wide open position of the I throttle.

It will be seen from the foregoing that the fuel and air contained infeed line 16 is a relatively constant mix ure at all times irrespectiveof the operating speed or load, and that this mixture is of suchrichness as to provide sufficient fuel to provide for the acingcorrespondingly increased in accordance.

celerating load. It will be understood, of course, that the presentsystem may operate with or without the auxiliary needle valve control,although in certain instances it may be desirable to embody in thesystem this auxilEary valve control.

As a general summary of the operation of the invention, it will be notedfirst that the fuel delivered to the pump or discharged to the engine iscontrolled in quantity by the air regulating device T, that is, theamount of fuel delivered to thepump at any one time is determined by theamount of air being taken into the engine, modified by the action of theauxiliary air control valve, and also by the position of the air inletthrottle. Then, although the fuel is proportioned in accordance with theflow of intake air, it is delivered to the engine cylinder entirelyseparate from the air. Furthermore, it will be apparent that by propertiming of the pump and injector valve with the engine, the engine may beoperated under practically any compression, inasmuch as the pump andinjector valve may be adjusted to deliver fuel to the engine cylinderduring any portion of either or both the piston compression and suctionstrokes.

It will be understood the drawings and description are to be consideredmerely as illustrative of and not restrictive on the broader claimsappended hereto, for various changes in design, structure andarrangement may be made Without departing from the spirit and scope ofsaid claims.

I claim:

1. The method of supplying fuel to an internal combustion engine, thatincludes feeding air to the engine in accordance with its varyingrequirements, metering fuel proportionate to the amount of air being fedto the engine, and introducing such metered fuel to the engineindependently of the said feed of air thereto.

2. The method of supplying a combustible air and fuel mixture to aninternal combustion engine, that includes feeding air to the engine inaccordance with its varying requirements, metering fuel proportionate tothe amount of air being fed to the engine, and introducing such meteredfuel together with supplemental air. to the engine independently of themain feed of air thereto.

3. The method of supplying a combustible air and fuel mixture to aninternal combustion engine, that includes feeding air to the engine inaccordance with its varying requirements, metering fuel proportionate tothe amount of a r being fed to the engine, and

introducing such metered fuel together with supplemental air, to theengine independentlv of the main feed of air thereto. the proportion ofsupplemental air to fuel being maintained substantially constant.

4:. The method of supplying fuel (to an internal combustion engine, thatincludes feedingair to the engine in accordance with its varyingrequirements, metering fuel proportionate to the amount of air being fedto the engine, and injecting such metered fuel under pressure into theengine independently of the said feed of air thereto.

5. The method of supplying fuel to an internal combustion engme, thatincludes feeding air to the engine in accordance with its varyingrequirements, metering fuel proportionate to the amount of air being fedto the engine, and injecting such metered fuel into the engine in timedrelation to the engine operation.

6. The method of supplying a combustible air and fuel mixture to aninternal combustion engine, that .includes feeding air to the engine inaccordance with its varying requirements, metering fuel proportionate tothe amount of air being fed to the engine, and injecting such meteredfuel together with supplemental air into the engine in timed relation tothe engine operation.

7. The method of supplying a combustible air and fuel mixture to aninternal combusti on engine, that includes feeding air to the engine inaccordance with its varying requirements, metering fuel proportionate tothe amount of air being fed to the engine,

and injecting such metered fuel'together with supplemental air into theengine in timed relation to the engine operation, the proportion ofsupplemental air to fuel being maintained substantially constant.

8. The method of supplying fuel to an internal combustion engine, thatincludes maintaining a restricted flow of air to the engine inaccordance with its varying requirements, metering fuel proportionate tothe amount of air being fed to the engine. by feeding and isolating thefuel by virtue of the varying depression caused by the air at itsrestricted point of flow, and introducing such metered fuel to theengine independently of the said air fed thereto.

9. The method of supplying a combustible air and fuel mixture to aninternal combustion engine, that includes maintaining a restricted flowof air to the engine in accordance with its varying requirements,metering fuel proportionate to the amount of air being fed to the engineby feeding and isolating the fuel by virtue of the varying depressioncaused by the air at its restricted point of flow, and introducing suchmetered fuel together with supplemental air, to the engine independentlyof the main air supply fed thereto.

10. The method of supplying a combustible air and fuel mixture to aninternal combustion engine, that includes maintaining a restricted flowof air to the engine in accordance with its varying requirements,metering fuel proportionate to the amount of air being fed to the engineby feeding and isolating the fuel by virtue of the varying depressioncaused by the air at its restricted point of flow, and introducing suchmetered fuel together with supplemental air, to the engine independentlyof the main air supply fed thereto, the proportion of supplemental airto fuel being maintained substantially constant.

11. The method of supplying fuel to an internal combustion engine, thatincludes maintaining a restricted flow of air to the engine inaccordance with its varying requirements, metering fuel proportionate tothe amount of air being fed to the engine by feeding and isolating thefuel by virtue of the varying depression caused by the air at itsrestricted point of flow, and pumping and injecting such metered fuelinto the engine in timed relation to the engine operation.

12. The method of supplying a combustible air and fuel mixture to aninternal combustion engine, that includes maintaining a restricted flowof air to the engine in accordance With its varying requirements,metering fuel proportionate to the amount of air being fed to the engineby feeding and isolating the fuel by virtue of the varying depressioncaused by the air at its restricted point of flow, and pumping andinjecting such metered fuel together with supplemental air into theengine in timed relation to the engine operation.

13. The method of supplying a combustible air and fuel mixture to aninternal combustion engine, that includes maintaining a restricted flowof air to the engine in accordance with its varying requirements,metering fuel proportionate to the amount of air being fed to the engineby feeding and isolating the fuel by virtue of the varying depressioncaused'by the air at its restricted point .of flow, and pumping andinjecting such metered fuel together with supplemental air into theengine in timed relation to the en gine operation, the proportion ofsupplemental air to fuel being maintained substantial-ly constant.

14. The method of supplying fuel to an internal combustion engine, thatincludes maintaining a restricted flow of air to the engine inaccordance with its varying requirements, metering fuel proportionate tothe amount of air being fed to the engine by lifting and isolating thefuel by virtue of the varying depression caused by the air at itsrestricted point of flow, and pumping and the engine, and compressingfuel together with supplemental air and injecting such air and fuel intothe engine. 16. The method of supplying a combustible air and fuelmixture to an internal combustion engine that includes periodicallycompressing air and fuel in timed relation to the engine operation, andadmitting such air and fuel to the engine when its compression pressurereaches a certain predetermined value. e

17. In a charge feeding system for internal combustion engines, an airinlet having therein a restriction, a constant level fuel chamber, meansactuated by the depression at the air passage restriction and operatingto feed and isolate fuel from the constant level fuel chamber, and afuel pump adapted to take fuel from the isolated fuel body and tointroduce such fuel to the engine.

18. In a charge feeding system for internal combustion engines, an airinlet having therein a restriction, a constant level fuel chamber, meansactuated by the depression at the air passage restriction and operatingto feed and isolate fuel from the constant level chamber, and a fuelpump adapted to take fuel from the isolated fuel body together with avolume of supplemental air and to introduce the mixture of fuel and airto the engine independent 5 of the main air feed thereto.

19. In a charge feeding system for internal combustion engines, an airinlet having therein a restriction, a constant level fuel chamber, meansactuated by the depression at the air passage restriction and operatingto feed and isolate fuel from the constant level chamber, and a fuelpump adapted to take fuel from the isolated fuel body together with avolume of supplemental air and to introduce the mixture of fuel and airto the engine independent of the main air feed thereto, and means formaintaining substantially constant the proportion of supplemental air tofuel.

20. In a charge feeding system for internal combustion engmes, an a1rinlet having therein a restriction, a constant level fuel chamber, meansactuated by the depression at the air passage restriction and operatingto feed and isolate fuel from the constant level fuel chamber,'a fuelpump adapted to take fuel from the isolated fuel body, and means forconducting fuel from said pump to and injecting said fuel into theengine at a predetermined pressure.

21. In a charge feeding system for internal combustion engines, an airintake passage, a constant level fuel chamber, means for withdrawing andmetering fuel from the constant level chamber controlled by the amountof air passing through the intake passage, and means independent of theintake passage to introduce such metered fuel to the engine.

22. In a charge feeding system for internal combustion engines, an airintake passage, a constant level fuel chamber, means for withdrawing andmetering fuel from the constant level fuel chamber controlled by theamount of air passing through the intake passage, and means for forciblyinjecting such metered fuel to the engine.

23. In a charge feeding system for internal combustion engines, an airintake passage, a constant level fuel chamber, means for withdrawing andmetering fuel from the constant level chamber controlled by the amountof air passing through the intake passage, a pump operated in timedrelation with the engine and taking fuel from metering means and meansconducting the output of said pump to the engine.

24. In a charge feeding system for internal combustion engines, an airintake passage, a constant level fuel chamber, means for withdrawing andmetering fuel from the constant level chamber controlled by the amountof air passing through the intake passage, a pump operated in timedrelation with the engine and taking fuel from the metering means, andmeans conducting the output of said pump to and injecting it into theengine.

, 25. In a charge feeding system for internal combustion engines, an airintake passage having a restricted portion, a depression chambercommunicating with said intake passage at the restricted portion, aconstant level fuel chamber communicating with said depression chamber,a pump operated in timed relation with the engine and taking fuel fromthe depression chamber, and means conductin the output of said pump toand injecting it into the engine.

26. In a charge feeding system for internal combustion engines, an airintake passage having a-- restricted portion, a depression chambercommunicating .with said intake passage at the restricted portion, aconstant level fuel chamber communicating with said depression chamber,an accelerating well'in said fuel chamber communicating with thedepression chamber, a pump operated in timed relation with the en ineand taking fuel from the depression cham er, and means conducting theoutput of said pump to and inj ecting it into the engine.

27. In a charge feeding system for internal combustion engines, an airintake passage havinga restricted portion, a depression chambercommunicating with said intake passage at the restricted portion, aconstant level fuel chamber communicating with said depression chamber,a pump operated in timed relation with the engine and taking fuel fromthe depression chamber, means in the depression chamber for lifting fueltherein for delivery to said pump, and means conducting the output ofsaid pump to and injecting it into the englne.

28. In a charge feeding system for internal combustion engines, an airintake passage having a restricted portion, a throttle valve in thepassage, a depression chamber communicating with said intake passage atthe restricted portion, a constant level fuel chamber communicating withsaid depression chamber, a'pump operated in timed relation with theengine and taking fuel from the depression chamber, means in thedepression chamber for feeding fuel and air to the pump, valve means inthe depression cham-- ber for regulating the flow of fuel and air to thepump in accordance with the movement of said throttle, and meansconducting the output of said pump to and injecting it into the engine.i

29. In a charge feeding system for internal combustion engines, an airintake passage having a restricted portion, a depression chambercommunicating with said intake passage at the restricted portion, aconstant level fuel chamber communicating with said depression chamber,a pump operated in timed relation with the engine and taking fuel fromthe depression chamber, a vertically extending inverted cup in thedepression chamber having its lower edge submerged beneath the liquidlevel therein, a tubular weir communicating with said pump and extendingthrough the bottom of said depression chamber and projecting above theliquid level within said cup, fuel being delivered to the pump byoverflowing said weir, and

means conducting the output of said pump to and injecting it into theengine.

30. In a charge feeding system for internal combustion engines, an airintake passage having a restricted portion, a throttle valve in thepassage, a depression chamber communicating with said intake passage atthe restricted portion, a constant level fuel chamber communicating withsaid depression;

chamber, a pump operatedin timed relation with the engine and takingfuel from the depression chamber, a vertically extending inverted cup inthe depression chamber having its lower edge submerged beneath theliquid level therein, a tubular weir communicating withsaid pump andextending through the bottom of said depression chamber and projectingabove the liquid level within said cup, fuel being delivered to the pumpby overflowing said weir, an auxiliary valve extending vertically withinthe cup and operatively connected to said throttle valve, said auxiliaryvalve being adapted to regulate the effective opening in the top of saidweirin accordance with the throttle valve position, and means conductingthe output of said pump to and injecting it into the engine.

31. In a charge feeding system for internal combustion engines, aconstant level fuel chamber, a cover for said chamber, a cup mounted onthe cover and extending downward below the fuel level in the fuelchamber, said cup defining a depression chamber,

depression chamber, a tubular Weir communicating with said pump andextending vertically through the bottom of said depression chamber andprojecting above the liquid level within said inverted cup, fuel beingdelivered to the pump by overflowing said weir, and means conductng theoutput of said pump to and injecting it into the engine.

32. In a charge feeding system for internal combustion engines, aconstant level fuel chamber, a cover for said chamber, a cup mounted onthe cover and extending ward below the fuel level in the fuel chamber,said cup defining a depression chamber, a plug in the upper end of thecup, an open ing in said cup extending into the fuel chamber beneath thefuel level therein to permit fuel to flow into the depression chamber,an inverted, cup in the depression chamber hav ing its lower edgesubmerged beneath the liquid level therein and depending from avertically adjustable stem threaded through said plug, an acceleratingwell, a passage communicating between the bottom ofisaid acceleratingwell and the depression chamber, and a tubular weir extending verticallythrough the bottom of said depression chamher and projecting above theliquid level within the first mentioned inverted cup, fuel in thedepression chamber being adapted to downyond the venturi, a depressionpassage opening into said venturi at its throat, a by-pass conduitinterconnecting said inlet and the depression passage, and means forclosing said by-passconduit at open and closed positions of thethrottle, the inlet and depression passage being in communication atintermediate positio ns of the throttle.

35. In a charge feeding system for internal combustion engines, atubular air intake passage having an inlet, a venturi adjacent theinlet, a throttle valve in the passage beyond the venturi and mounted ona shaft extending diametrically across the passage, a separate andcylindrical valve chamber mounted on the side of the intake passage saidshaft,"the auxiliary valve being shaped to provide a pair of arms forslidably engaging the cylindrical chamber wall on each side of one ofsaid openings at an intermediate'position of the/throttle, said armsbeing adapted to close the last me'ntionedopening respectively when'thethrottle valve is moved to open and closed positions.

36. In a charge feeding system for internal combustion engines, an airintake assage having an air inlet and a venturi in t e passage beyondthe inlet, a depression chamber communicating with a constant level fuelchamber, a depression passage extending from said depression chamber andopening into the throat of the venturi, a pump operated in timedrelation with the engine and taking fuel from the'engine, and means conducting the out ut of said pump to and injecting it into t e engine. I

37 In a charge feeding system for internal combustion engines, an air"intake assage having an inlet, a venturi adjacent t e inlet and athrottle valve in the passage beyond the venturi, a depression chambercommunicating with a constant level fuel chamber, a depression passageextending from said depression chamber and opening into thethroat of theventuri, a by-pass conduit interconnecting said inlet and the depressionpassage,

means for closing the by-pass conduit at open and closed positions ofthe throttle, a pump operated in timed relation with the engine andtaking fuel from the depression chamber, and means conducting the outputof said pump to and injecting it into the engine.

38. In a charge feeding system for internal combustion engines, an airintake passage having an inlet, a venturi adjacent the inlet and athrottle valve in the passage beyond the venturi, a depression chambercommunicating with a constant level fuel chamber, a depression passageextending from said depression chamber and opening into the throat ofthe venturi, a by-pass conduit interconnecting said inlet and thedepression passage,

means for closing the by-pass conduit at open and closed positions ofthe throttle, a conduit interconnecting said inlet with the constantlevel fuel chamber above the liquid level therein, a pump operated intimed relation with the en inc and taking fuel from the depression camber, and means conducting the output of said pump to and injecting itinto the engine.

In witness that I claim the fore oing I have hereunto subscribed my nametfiis 17th day of September, 1928.

ROYF. ENSIGN.

